cp's OEIS Frontend

A204268 Permanent of the n-th principal submatrix of A204267.

%I A204268 #9 Jan 06 2018 10:59:14
%S A204268 0,1,9,16,132,1032,5184,51912,530712,4188672,53529984,707802624,
%T A204268 7614259200,119716185600,1938416832000,26579819520000,496487584512000,
%U A204268 9509523337728000,158654296829952000,3434389946233344000
%N A204268 Permanent of the n-th principal submatrix of A204267.
%H A204268 G. C. Greubel, <a href="/A204268/b204268.txt">Table of n, a(n) for n = 1..100</a>
%t A204268 f[i_, j_] := Mod[i + j + 1, 3];
%t A204268 m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
%t A204268 TableForm[m[8]] (* 8x8 principal submatrix *)
%t A204268 Flatten[Table[f[i, n + 1 - i],
%t A204268   {n, 1, 14}, {i, 1, n}]]    (* A204267 *)
%t A204268 Permanent[m_] :=
%t A204268   With[{a = Array[x, Length[m]]},
%t A204268    Coefficient[Times @@ (m.a), Times @@ a]];
%t A204268 Table[Permanent[m[n]], {n, 1, 22}]  (* A204268 *)
%Y A204268 Cf. A204267.
%K A204268 nonn
%O A204268 1,3
%A A204268 _Clark Kimberling_, Jan 15 2012